%0 Journal Article
%@ 1631-0713
%A Ledésert, Béatrice
%A Hebert, Ronan
%A Genter, Albert
%A Bartier, Danièle
%A Clauer, Norbert
%A Grall, Céline
%A Géosciences et environnement Cergy, université de Cergy-Pontoise,France,
%A Géosciences et environnement Cergy, université de Cergy-Pontoise,France,
%A Groupement européen d’intérêt économique exploitation minière de la chaleur,  France,
%A Muséum national d’histoires naturelles,France,
%A LHyGeS (Laboratoire d’hydrologie et de géochimie de Strasbourg) (CNRS/UDS),France,,
%A Géosciences et environnement Cergy, université de Cergy-Pontoise,France,
%D 2010
%F epos:1852
%I Elsevier
%J Comptes Rendus Geoscience
%K Soultz granite; Fracture network; Hydrothermal alterations; Permeability; Illite; Calcite; France
%N 7-8
%P 607-615
%T Fractures, hydrothermal alterations and permeability in the Soultz Enhanced Geothermal System
%U https://episodesplatform.eu/eprints/1852/
%V 342
%X Borehole studies of the Soultz-sous-Forêts granite are dedicated to deep geothermics. The hydraulic properties of the reservoir are mainly controlled by the occurrence of some altered cataclastic shear zones showing a low natural permeability characterized by the occurrence of brines. Those zones show a fracture cluster organisation with sealed fractures of various types (post-filled joints, sheared fractures, veins). The main hydrothermal deposits observed within the permeable zones are geodic quartz, carbonates, illite and more locally sulphides. The fracture wall–rocks are intensely transformed: dissolution of igneous minerals, crystallization of new minerals, porosity and permeability increase. It is important to characterize the newly-formed minerals in order to choose the reagents used to improve the permeability of the exchanger by chemical stimulations. This article represents a synthesis of the studies completed by the authors between 1990 and 2008 on the fracture networks, hydrothermal alterations and mineral crystallizations they induced and data about the flow pathways in the exchanger.